US3213030A - Cleansing and laundering compositions - Google Patents

Description

United States Patent O 3,213,030 CLEANSING AND LAUNDERING COMPOSITIONS Francis L. Diehl, Cincinnati, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio N Drawing. Filed Mar. 18, 1963, Ser. No. 266,025 12 Claims. (Cl. 252-152) This invention relates to cleansing and laundering compositions, and more especially to built cleansing and laundering compositions containing so-called builder materials that serve to enhance the cleaning capacity of synthetic nonsoap detergent compounds.

The use of builders as adjuncts to soap and synthetic detergents, and the property which some materials have of improving cleaning levels of such detergent compounds are well known phenomena. The phenomena are widely appreciated but the exact behavior and mechanics of how builders perform their function has never been fully explained. While explanations for the behavior of builders may be found, there still has not been determined a set of criteria which would permit one to accurately predict which compounds actually possess significant builder properties.

This may be explained, in part, by the complex nature of detergency itself and the countless factors which are conceptually involved. Among the many facets of built detergency systems in which builder materials are thought to have some effect are such factors as stabilization of solid soil suspensions, emulsification of soil particles, the surface activity of the aqueous detergent solution, solubilization of Water-insoluble materials, foaming or suds producing characteristics of the washing solution, peptization of soil agglomerates, neutralization of acid soil, and the inactivation of mineral constituents present in the washing solution. There might be mentioned other areas in which a builder material might be of some assistance. The point is that no general basis has been found either as regards physical properties or chemical structure by which one might predict the behavior of chemical materials as detergency builders.

Among the builder materials described in the prior art, are water-soluble inorganic alkaline builder salts which are used alone or in combination. Examples are alkali metal carbonates, borates, phosphates, polyphosphates, bicarbonates and silicates.

Examples of organic builder compounds known heretofore and which also can be used alone and in combination are alkali metal, ammonium or substituted ammonium aminopolycarboxylates, e.g., sodium and potassium ethylenediaminetetraacetate, sodium and potassium N-(2-hydroxyethyl)-ethylenediaminetriacetate, sodium and potassium nitrilotriacetate and sodium, potassium and triethanolammonium N (2 hydroxyethyl) nitril-odiacetate. Alkali metal salts of phytic acid, e.g., sodium phytate are also suitable as organic builders.

An ever increasing interest in builder performance has resulted in an expanding list of compounds which, when used in conjunction with detergents, serve to enhance the cleaning performance of such detergents. This increased interest has brought about the fuller appreciation that improved, more eflicient builders are highly desirable to avoid certain limitation-s and disadvantages of prior art builder materials.

One of the known problems associated with the widely used series of condensed inorganic polyphosphate compounds such as alkali metal tripolyphosphates, and higher condensed phosphates is their tendency to hydrolyze when used in aqueous detergent systems into less condensed phosphorus compounds. Such less condensed forms include, for example, orthophospates which are relatively inferior builders and, in fact, may form undesirable precipitates in an aqueous solution.

It is a primary object of this invention to provide a new class of improved builder compounds which are markedly more efficient and more stable to hydrolysis in aqueous solutions than previously known, widely used builder-s. Another object is to provide improved cleansing and laundering compositions containing, as the builder material, a water-soluble salt of methylenediphosphonic acid. A yet further object is to provide improved built detergent compositions in which the builder material is a water-soluble salt of methylenediphosphonic acid and which built compositions are surprisingly effective in cool water.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustrations only, since various changes and modifications within the spirit and scope of the invention will become apparent from this detailed description to those skilled in the art.

It surprisingly has been discovered that water-soluble salts of methylene diphosphonic acid possess outstanding builder properties and that they are highly efiicient in that capacity. Moreover, it has been discovered that these compounds can be used to build detergent compositions containing a broad range of synthetic non-soap detergent surfactant materials, including anionic, nonionic, ampholytic and zwitterionic detergent surfactant compounds.

Another completely unexpected discovery is the superior performances of the water-soluble salts of methylenediphosphonic acid in enhancing the cleaning power of detergent surfactants in cool water. The term cool water as used herein is water having a temperature Within the range of about 40 F. to about 100 F. A washing formulation possessing high cleansing performance within this temperature range has obvious advantages to the consumer. Such advantages include, for instance, substantial savings in water heating costs as well as longer life of delicate fabrics and materials (synthetics such as nylon, Dacron, as well as Woolens and silks) which cannot tolerate the harsh treatment of severe hot water (e.g., 100 F.-220 F.) washings. It is well known, for instance, that certain fabrics have a pronounced tendency to shrink, wrinkle, or draw up when washed in such hot water.

The novel class of builder compounds according to this invention are the Water-soluble salt derivatives of methylenediphosphonic acid which has the following molecular formula, CH (PO H The acid and the salts thereof may be prepared in any suitable manner, no claim being made herein for their preparation. An excellent method of preparing the compounds of this invention is disclosed in copending patent application Serial No. 218,862, filed on August 23, 1962, by Clarence H. Roy.

A readily crystallizable form of the new builder compound has three of the acid hydrogens replaced by an alkali metal such as sodium. Hence, the salt commonly prepared and used is the trisodium salt which gives a pH of 10.5 at a concentration of 0.1% by weight in distilled Water having a temperature of F. The anhydrous trisodium salt has the structure While any alkali metal or ammonium or substituted ammonium salt form can be used as the builder according to this invention, the trisodium salt, the tetrasodium salt and mixtures thereof are the preferred forms. Mixtures of the tetrasodium and trisodium salts give a pH in water solution from about 8 to 12. Each of the lesser neutralized forms such as monosodium and disodium derivatives or the free acid have builder capacity comparable to the trisodium and tetrasodium salt forms, provided that additional alkali is added, if necessary, to adjust the pH of the washing solution to be within about 8 to about 12. The builder compounds of this invention perform best at this pH range. The standard alkaline materials can be used for this purpose when necessary such as alkali metal silicates, phosphates, borates and carbonates. Free alkali materials such as sodium and potassium hydroxides can also be used.

Hereinafter in this specification the novel builder com pound is referred to conveniently as MDP. This expression is intended to broadly cover the acid as well as the various neutralized salt forms thereof, unless otherwise specified.

As mentioned above, it has already been suggested to combine various types of builder salts with synthetic detergent compounds to produce built detergent compositions. As far as is known, however, no one prior to this invention has discovered that the particular builder compounds described herein, oflfer as advantages, stability against deterioration during storage and use, superior builder efiiciency, outstanding performance in hard Water, as well as increased efficiency at cool water temperatures. The specific proportions and ratios employed in preparing the improved detergent compositions of this invention are also an important aspect of this invention. Unless otherwise specified, all ratios given herein are by weight ratios.

These and other advantages are obtained, according to this invention, by providing cleansing and laundering compositions consisting essentially of a detergent surfactant compound and, as a builder, a water-soluble salt of methylenediphosphonic acid, such as the sodium or potassium salts, the ratio by weight of the builder to the detergent surfactant compound being in the range of about 1:3, to about 10:1, said composition providing in solution a pH of between about 8 to 12. The preferred ratio of said builder to said detergent surfactant compound is in the range of about 1:2 to about 5:1 and the optimum pH range is to 11.5.

Among the detergent surfactant compounds which can be successfully built by the builder compounds of this invention and which are clearly within the contemplation of this invention are the following examples:

(a) Anionic synthetic detergents: This class of synthetic detergents includes alkali metal salts of organic sulfuric reaction products having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon aoms and a radical selected from the group consisting of sulfonic acid and sulfuric acid ester radicals. (Included in the term alkyl is the alkyl portion of high acyl radicals.) Important examples of the synthetic detergents which form a part of the preferred compositions of the present invention are the sodium alkyl sulfates, especially those obtained by sulfating the higher alcohols (C C carbon atoms) produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkylbenzenesulfonates, in which the alkali group contains from about 9 to about carbon atoms, especially those of the types described in United States Letters Patent Numbers 2,220,- 099, and 2,477,383; sodium alkylglycerylethersulfonates, especially those ethers of the higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfates and sulfonates; sodium or potassium salts of sulfuric acid esters of the reaction product of one mole of a higher fatty alcohol (e.g., tallow or coconut oil alcohols) and about 1 to 6 moles of ethylene oxide; sodium or potassium salts of alkylphenol ethylene oxide ether sulfate with about 1 to about 10 units of ethylene oxide per molecule and in which the alkyl radicals contain about 9 to about 12 carbon atoms; the reaction product of fatty acids esterified with isethionic acid and neutralized with sodium hydroxide, where, for example, the fatty acids are derived from coconut oil; sodium or potassium salts of fatty acid amide of a methyltauride in which the fatty acids, for example, are derived from coconut oil; and others known in the art, a number being specifically set forth in United States Letters Patent Numbers 2,486,922 and 2,396,278.

(b) Nonionic synthetic detergents: This class of synthetic detergents may be broadly defined as compounds, aliphatic or alkyl aromatic in nature, which do not ionize in water solution.

For example, a well known class of nonionic synthetic detergents is made available on the market under the trade name of Pluronic. These compounds are formed by condensing ethylene oxide with an hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water-insolubility has a molecular weight of from about 1200 to 2500. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water-solubility of the molecule as a whole and the liquid character of the product is retained up to the point where polyoxyethylene content is about 50% of the total weight of the condensation product.

Other suitable nonionic synthetic detergents include:

(1) The polyethylene oxide condensates of alkylphenols, e.g., the condensation products of alkyl-phenols or dialkylphenols wherein the alkyl group contains from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 10 to 25 moles of ethylene oxide per mole of alkylphenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, n-octane, or n-nonane for example.

(2) Those nonionic synthetic detergents derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylenediamine. For example, compounds containing from about 40% to about polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylenediamine and excess propylene oxide, said base having a molecular weight of the order of 2500 to 3000, are satisfactory.

(3) The condensation product of aliphatic alcohols having from 8 to 18 carbon atoms, in either straight chain or branched chain configuration, with ethylene oxide, e.g., a coconut alcohol-ethylene oxide condensate having from 10 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms.

(4) Long chain tertiary amine oxides corresponding to the following general formula, R R R N+O, wherein R is an alkyl radical of from about 8 to 18 carbon atoms, and R and R are each methyl or ethyl radicals. The arrow in the formula is a conventional representation of a semi-polar bond. Examples of amine oxides suitable for use in this invention include dimethyldodecylamine oxide, dimethyloctylamine oxide, dimethyldecylamine oxide, dimethyltetradecylamine oxide, dimethylhexa decylamine oxide.

(5) Long chain tertiary phosphine oxides corresponding to the following general formula RRR"P O wherein R is an alkyl, alkenyl or monohydroxyalkyl radical ranging from 10 to 18 carbon atoms in chain length, and R and R are each alkyl or monohydroxyalkyl groups containing from 1 to 3 carbon atoms. The arrow in the formula is conventional representation of a semi-polar bond. Examples of suitable phosphine oxides are: dimethyldodecylphosphine oxide, dimethyltetradecylphosphine oxide, ethylmethyltetradecylphosphine oxide, cetyldimethylphosphine oxide, dimethylstearylphosphine oxide, cetylethylpropylphosphine oxide, diethyldodecylphosphine oxide, diethyltetradecylphosphine oxide, dipropyldodecylphosphine oxide, bis-(hydroxymetbyl) dodecylphosphine oxide, bis-(2-hydroxyethyl)dodecylphosphine oxide, (2- hydroxypropyl)methyltetradecylphosphine oxide, dimethyloleylphosphine oxide, and dimethyl-(Z-hy-droxydodecyl) phosphine oxide.

Ampholytic synthetic detergents: This class of synthetic detergents can be broadly described as derivatives of aliphatic amines which contain a long chain of about 8 to 18 carbon atoms and an anionic water solubilizing group, e.g., carboxy, sulfo, or sulfato. Examples of compounds falling within this definition are sodium-3- dodecylamino-proprionate and sodium 3-dodecylaminopropanesulfonate.

(d) Zwitterionic synthetic detergents: This class of synthetic detergents can be broadly described as derivatives of aliphatic quaternary ammonium compounds, in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one contains an anionic water solubilizing group, e.g., carboxy sulfo or sulfato. Examples of compounds falling within this definition are 3-(N-dimethyl-N-hexadecylammonio)- propane-l-sulfonate and 3-(N,Ndimethyl-N-hexadecylammonio)-2-hydroxypropane-l-sulfonate.

The anionic, nonionic, ampholytic and zwitterionic detergent surfactants mentioned above can be used singly or in combination in the practice of the present invention. The above examples are merely specific illustrations of the numerous detergent surfactants which can find application within the scope of this invention.

The foregoing detergent surfactant compounds can be built into any of the several commercially desirable composition forms, for example, granular, flake, liquid and tablet form.

Granular detergent compositions prepared according to one embodiment of this invention can contain the MDP builder salts and the detergent surfactants in the ratio of about 1:3 to about 10:1 by weight. The preferred ratio of builder to active for granular compositions is about 1:2 to about :1. On the other hand, the preferred ratio in built liquid compositions of MDP builder salts to detergent surfactants is about 1:2 to about 3:1.

The detergent compositions described by this invention, employing MDP salts as a builder, offer their greatest advantage in the area of built liquid detergents designed for use in cool water although excellent cleaning results are obtained with conventional hot water usage. Built liquid detergents present special problems to the formulator in view of the peculiarities inherent in aqueous or alcoholic systems such as solubility of the ingredients and more especially, the stability of the ingredients in such systems. It is well known, as mentioned previously, that sodium tripolyphosphate, while outstanding in its behavior in granular compositions, is generally regarded as being unsuited for use in built liquid detergents. Thus, as a practical consideration, there has been a necessity of resorting to alkali metal pyrophosphates such as Na P O or K P O in order to prepare a built liquid detergent. This has been true notwithstanding the known inferiority of pyrophosphate salts to sodium tripolyphosphate, for example, as builders for heavy duty detergent compositions. These advantages are overcome by the builder compounds of this invention. The MPD builder salts are even more stable against hydrolysis than pyrophosphate builders. In built liquid compositions, the potassium salt is preferred over the sodium salt due to increased solubility characteristics of the former.

In view of the increasing acceptance by the general public of built liquid detergents for virtually all washing and cleaning situations including laundering and dishwashing, it is a very significant contribution of this invention that an improved built liquid detergent product is made possible that will provide detergency levels comparable to and, in some respects, superior to a sodium tripolyphosphate or sodium pyrophosphate built liquid product.

Most of the built liquid detergents commercially available at the present time are either water based or have a mixture of water and alcohol as the liquid vehicle. Such vehicles can be employed in formulating a built liquid detergent using MDP as a builder without fear of encountering stability problems. Accordingly, a built detergent composition of this invention can consist essentially of a water-soluble MDP salt and a detergent surfactant in the ratios above described and the balance being a vehicle medium, for example, water or a water alcohol mixture.

In a finished detergent formulation of this invention regardless of physical form there will often be added, in minor amounts, materials which make the product more effective or more attractive. The following are mentioned by way of example. Water-soluble sodium carboxyrnethyl cellulose may be added in minor amounts to inhibit soil redeposition. A tarnish inhibitor such as benzotriazole or ethylenethiourea may also be added in amounts up to about 2%. Pluorescers, perfume and color while not essential in the compositions of the invention, can be added in amounts up to about 1%. An alkaline material or alkali, such as sodium hydroxide or potassium hydroxide, can be added in minor amounts as supplementary pH adjusters when needed. There can also be mentioned as suitable additives, brightening agents, sodium sulfate, and sodium carbonate.

Corrosion inhibitors generally are also added. Soluble silicates are highly effective inhibitors and can be added to certain formulas of this invention at levels of from about 3% to about 8%. Alkali metal, preferably potassium or sodium, silicates having a weight ratio of sio :M o of from 1.0:1 to 2.8:1 can advantageously be used. M in this ratio refers to sodium or potassium. A sodium silicate having a ratio of SiO :Na O of about 1.6:1 to 2.45:1 is especially preferred for economy and effectiveness.

In the embodiment of this invention which provides for a built liquid detergent, a hydrotropic agent at times is found desirable. Suitable hydrotropes are watersoluble alkali metal salts of toluenesulfonate, benzenesulfonate, and xylenesulfonate. The preferred hydrotropes are the potassium or sodium toluenesulfonates. The hydrotrope salt can be added, if desired, at levels of 0% to about 12%. While a hydrotrope will not ordinarily be found necessary, it can be added if so desired, for any reason including the preparation of a product which retains its homogeneity at a low temperature.

The following examples will illustrate but not limit the compositions of this invention.

EXAMPLE I An excellent built liquid detergent formulation according to this invention has the following composition, in which the percentages are by weight.

Percent Sodium dodecylbenzenesulfonate (the dodecyl radical being a polypropylene, predominantly tetrapropylene averaging 12 carbon atoms) 10.0 Dimethyldodecylamine oxide 10.0 Methylenediphosphonic acid 10.0 Potassium hydroxide 7.9 Potassium toluenesulfonate 8.0 Sodium silicate (ratio SiO :Na O of 2.45:1) 3.8 Carboxymethyl hydroxyethyl cellulose 0.3

Water, balance.

In preparing this composition the potassium hydroxide reacts with the methylenediphosphonic acid to form a builder salt, tripotassium methylenediphosphonate. In formulating this composition the methylenediphosphonic acid should be mixed with the potassium hydroxide prior to the addition of sodium silicate.

Performance of this detergent composition is excellent in laundry tests as Well as dishwashing evaluations. Its resistance to hydrolysis makes possible cleaner washes as well as longer shelf life since the MDP builder r ma ns in its active form through the complete washing cycle notwithstanding the large amounts of water present in the formulation as well as the washing solution.

EXAMPLE II An excellent granular detergent composition giving excellent cleaning and whiteness maintenance results With cool water or hot water has the following ingredients in the weight percentages indicated:

Percent 1:1 mixture of sodium hexadecyl-Z-hydroxythiosulfate and sodium octadecyl-Z-hydroxythiosulfate 17.5 Trisodium methylene diphosphonate 55.0 Sodium silicate (ratio SiO of 2:1) 6.0 Sodium sulfate 13.8 Coconut fatty acid ethanolamide 2.7 Water 5.0

EXAMPLE III A granular detergent composition having the following formulation performs effectively in laundering and other household cleaning situations employing Water at cool or warm temperatures.

Percent Sodium dodecylbenzenesulfonate (dodecyl group derived from tetrapropylene) Pluronic L-64-F68 mixture* 2.0 Hydrogenated marine oil fatty acid 2.2 Trisodium methylenediphosphonate 59.6 Sodium silicate (ratio SiO :Na O of 2:1) 9.7 Sodium sulfate 13.5

Water 5.5

Condensation products of ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol and having molecular Weights of approximately 3000 and 8000, respectively.

Laundering performance characteristics of this composition are exceptionally good from the point of view of general cleaning and whiteness maintenance performance.

EXAMPLE IV Another highly effective granular detergent offering equally good laundering performance in the area of cleaning, whiteness, and whiteness maintenance has the following formulation:

Percent An effective cool water heavy duty built liquid detergent which performs exceptionally well, especially in the areas of cleaning and whiteness maintenance has the following composition:

Percent 3 (N,N-dimethyl-N-coconutammonio) -2-hydroxypropanel-sulfonate 9.0 Tergitol 12-P-12 (condensation product of 12 moles of ethylene oxide and one mole of dodecyl phenol) 3.0

Tripotassium methylene diphosphonate 26.0

Sodium silicate (SiO :Na O- l.6: 1) 3.0 Potassium toluenesulfonate 8.5 Sodium carboxymethyl hydroxyethyl cellulose .3 Fluorescent dye .12 Perfume .15

Benzotriazole .03

Water 49.90

EXAMPLE VI An effective cool water granular built composition according to this invention has the following composition:

Percent 3 (N,N-dimethyl-N-hexadecylammonio -propanel-sulfonate 17.0 Trisodium methylenediphosphonate 45.0 Sodium silicate (SiO :Na O=2.5 :1) 6.0 Sodium carboxymethyl cellulose .5 Sodium sulfate 28.0

Water 3.5

Whiteness maintenance and cleaning performance results obtained by laundering with this composition are very good.

Three different performance characteristics of the new builder compounds were evaluated: cleaning, whiteness and whiteness maintenance. For the purpose of this invention, these terms have the following meanings. The term cleaning means the ability of a built laundering composition to remove deeply embedded soil lines or deposits such as occur at the collars and cuffs of white shirts. Whiteness is a more general term which is a measurement of the ability of a built laundering composition to whiten areas which are only slightly or moderately soiled. Whiteness maintenance is a term used to describe the ability of a laundering composition to prevent the soil, which has been removed during the washing process from being redeposited upon the fabrics during the remainder of the washing cycle. Test methods are described below.

The surprising building ability of the methylene diphosphonate (MDP) salts of this invention were determined by washing naturally soiled white dress shirts with detergency compositions built with different builder materials. Shirts with detachable collars and cuffs were worn by male subjects under ordinary conditions for two normal working days. The collars and cuffs were then detached and washed in a small agitator type machine using solutions of the detergent compositions to be evaluated. The specific washing conditions are described below.

After being washed and dried, the collars and cuffs being graded were visually compared with other collars and cuffs, which had been similarly worn and soiled, but which were washed with a standard detergent composition. This visual comparison was made by a group of five people who were unfamiliar with the structure and purpose of the test and who formed their judgments independently.

Their visual judgments were expressed on a scale ranging from zero to ten where zero represents the cleaning level obtained by washing with water alone and a value of ten represents the cleaning level of an excellent standardized detergent composition under optimum conditions. For purposes of this evaluation, a valve grade of five on this scale represents a level of cleaning that is considered satisfactory in household practice.

The test method described above was conducted employing washing compositions that consisted solely of a detergent surfactant and a builder compound.

One of the builders used was sodium tripolyphosphate, STP, which is very widely used in commercially available compositions and trisodium methylenediphosphonate, MDP, was selected as the representative builder salt compound of this invention. Each builder was tested with each of several non-soap synthetic detergent surfactants including 3-(N,N-dimethyl-N-hexadecylarnmonio)-propane-l-sulfonate, a 1:1 mixture of sodium hexadecyl-2-hydroxythiosulfate and sodium octadecyl-Z-hydroxythiosulfate, and Tergitol 12-P-12, which is a commercially available dodecyl phenyl polyethylene glycol ether product containing 12 moles of ethylene oxide per mole of dodecyl phenol.

The concentration of the surfactant in the washing solution was constant at .03% by weight. MDP as a builder was also tested only at .03% concentration by Weight. STP was tested at .03% and also at .06% concentration by Weight in order to determine and compare MDP performance with STP performance over a range of higher and lower STP concentrations. No fluorescers, bleaches, or anti-redeposition agents were used to prevent any interference or masking over of the performance of the builders used.

The washing solutions containing seven grains (equivalent CaCO per gallon hardness were adjusted with NaOH to a pH of 11 at an initial temperature of 80 F. The duration of the washing cycle was minutes.

The results of these tests are presented in Table I.

The data presented in Table I evidences the increased cleansing efiiciency of trisodium methylenediphosphonate over sodium tripolyphosphate as a builder compound under the test conditions. It will be noted that at equal builder concentrations, .03%, the MDP salt consistently attained substantially higher scores with each of three different surfactants tested. (Compare Column A with Column B in Table I.) In fact, the surprising fact is that the cleaning levels obtained with .03% concentration of the MDP salt were almost equal to the cleaning results obtained with STP at .06%. (Compare Column B with Column C.)

The significance of these experimental results is that, as a result of this invention, it is now possible, at cool water temperatures, e.g., 80 F. to use only one half of the ordinary concentration of builder generally recommended for good washing results without sacrificing cleaning performance. Thus, economic savings can be enjoyed in household situations as a result of using less of the builder compound of this invention as well as the additional savings of not having to heat the Water to usual high temperatures.

The collar and cuff samples washed with the detergent compositions described in Table I were thereafter examined for whiteness performance results and the comparative values are presented in Table 11, below.

Whiteness measurements were made on the backs of the naturally soiled ends with a commercially available photoelectric reflectometer, i.e., a Hunter Color and Color- Ditference meter manufactured by Henry A. Gardner Laboratory, Inc. This instrument is designed to distinguish color differences and operates on the tristimulus colorimeter principle wherein the 45 degree diffuse reflectance of an incident light beam on a test specimen is measured through a combination of green, blue and amber filters. The electrical circuitry of the instrument is so designed that lightness and chromaticity values for the test specimen are read directly. The department from white (MgO being taken as a standard white) of the test specimen is calculated by introducing the lightness and chromaticity values so obtained into a complex formula supplied by the manufacturer. An evaluation of relative whiteness performance compared to a standard detergent composition is thus obtained for the test formulations. These are later compared with other values obtained from other test samples.

A more comprehensive description of this instrument and its mode of operation appears in Color in Business, Science and Industry, by Deane B. Judd, pages 260262; published by John Wiley & Sons, New York (1952).

Table II.Whizeness Evaluation The whiteness figures presented in Table II above illustrate the superior whiteness results obtained with MDP built laundering compositions with several surfactants. The higher figures indicate better whiteness levels, i.e., less departure from a standard white. It should be noted that at equal weight concentrations of respective builder materials, i.e., .03% STP and .03% MDP, the MDP whiteness values are markedly higher. (Compare Column A with Column B in Table II.) Very surprisingly, the whiteness results obtained with 0.3% MDP are about equal to or even substantially better than the whiteness results obtained with STP at twice that concentration, i.e., .06% concentration. (Compare Column B with Column C in Table II.)

The whiteness maintenance evaluation was performed by the following method. Unsoiled swatches of cotton terrycloth were added to the collar and cuff samples which were washed according to the above cleaning and white ness examples. The swatches were thereafter independently evaluated to determine the whiteness maintenance property of the particular built laundering compositions. As mentioned above, soil carried by the cotton terrycloth swatches after the washing cycle represents soil which was removed from the soiled fabrics, suspended in the washing solution and redeposited on the fabrics. This type of soil redeposition is a serious matter and compositions offering improved results in this area are constantly being sought.

The same measuring procedure employing the Hunter Color and Color-Difference Meter was followed in this experiment as in the measurement of whiteness. Thus, the figures in Table III below are whiteness maintenance grades calculated from data obtained by grading the cotton terrycloths washed with the detergent compositions described above. Increasing values again represent better performance results.

It will be seen from the data in Table III that superior whiteness maintenance results are obtained with MDP than with STP used at equal concentrations (compare Column A with Column B in Table III). Surprisingly, MDP used at .03% concentrations is very substantially better in whiteness maintenance performance than even when STP is used at concentrations of .06% (compare Column B with Column C in Table III).

The preceding laundering tests illustrate very well the excellent overall detergency results attained with the methylenediphosphonate builder compounds of this invention based on comparisons with a sodium tripolyphosphate builder. Moreover, similarly good performance results in areas of cleaning, whiteness and whiteness maintenance are obtained when MDP is employed to build other detergent surfactants besides those for which performance data is presented above. While not complete, a list of suitable synthetic non-soap detergent compounds which can be used appears above. The novel builder compounds of this invention comprising water-soluble salts of methylenediphosphonic acid can be used alone as detergent builders, or they can be used in admixture with other organic and inorganic builder materials.

What is claimed is:

1. An improved cleansing and laundering composition consisting essentially of a water-soluble salt of methylene diphosphonic acid selected from the group consisting of the sodium, potassium, ammonium, and substituted ammonium salts of said acid as a builder and a water-soluble organic synthetic non-soap detergent selected from the group consisting of anionic, nonionic, zwitterionic, ampholytic detergents, and mixtures thereof, the ratio of said builder to said detergent being in the range of about 1:3 to about 10:1, said composition providing in aqueous solution a pH between about 8 and about 12.

2. The composition of claim 1 wherein the ratio of said builder to said detergent is in the range of about 1:2 to about :1.

3. The composition of claim 1 wherein the pH range of the solution is between 10 and 11.5.

4. A cleansing and laundering composition of improved cleaning efficiency consisting essentially of a watersoluble trisodium salt of methylenediphosphonic acid as a builder and an organic water-soluble synthetic non-soap detergent, selected from the group consisting of anionic, nonionic, zwitterionic, ampholytic detergents, and mixtures thereof, the ratio of said builder to said detergent being in the range of about 1:3 to about 10:1, said composition providing in aqueous solution a pH between about 8 and about 12.

5. A heavy duty built .liquid detergent composition especially effective in cool water consisting essentially of a liquid vehicle, a water-soluble tripotassium salt of methylenediphosphonic acid as a builder and an organic watersoluble non-soap synthetic detergent selected from the group consisting of anionic, nonionic, zwitterionic, ampholytic detergents, and mixtures thereof, the ratio of said builder to said detergent being in the range of about 1:3 to about 10:1, said composition providing in aqueous solution a pH between 8 and 12.

6. An improved cleansing and laundering composition consisting essentially of a water soluble trisodium salt of methylenediphosphonicacid as a builder and as a detergent, 3-(N,N-dimethyl-N-hexadecylammonio)-propane-lsulfonate, said composition providing in aqueous solution a pH between about 8 and about 12.

7. An improved cleansing and laundering composition consisting essentially of a water soluble trisodium salt of methylenediphosphonic acid as a builder and as a detergent, 3-(N,N-dimethyl-N-coconutammonio) Z-hydroxypropane-l-sulfonate, said composition providing in aqueous solution a pH between about 8 and about 12.

8. An improved cleansing and laundering composition consisting essentially of a water soluble trisodium salt of methylenediphosphonic acid as a builder and as a detergent, an anionic water soluble alkali metal salt of an organic sulfuric reaction product having in its molecular structure an alkyl radical having 8 to 22 carbon atoms and a sulfonic acid radical, said composition providing in aqueous solution a pH between about 8 and about 12.

9. An improved cleansing and laundering composition consisting essentially of a water soluble trisodium salt of methylenediphosphonic acid as a builder and as a detergent, an anionic water soluble alkali metal salt of an organic sulfuric reaction product having in its molecular structure an alkyl radical having 8 to 22 carbon atoms and a sulfuric acid ester radical, said composition providing in aqueous solution a pH between about 8 and about 12.

10. The cleansing and laundering composition'of claim 9 wherein the anionic detergent is sodium alkyl sulfate in which the alkyl substituent contains from about 8 to about 18 carbon atoms.

11. The cleansing and laundering composition of claim 8 wherein the anionic detergent is sodium alkylbenzenesulfonate in which the alkyl group contains from about 9 to about 15 carbons atoms.

12. The cleansing and laundering composition of claim 8 wherein the anionic detergent is potassium alkylbenzenesulfonate in which the alkyl group contains from about 9 to about 15 carbon atoms.

References Cited by the Examiner FOREIGN PATENTS 12/58 Germany.

2/62 Great Britain.

Claims (1)

1. AN IMPROVED CLEANSING AND LAUNDERING COMPOSITION CONSISTING ESSENTIALY OF A WATER-SOLUBLE SALT OF METHYLENE DIPHOSPHONIC ACID SELECTED FROM THE GROUP CONSISTING OF THE SODIUM, POTASSIUM, AMMONIUM, AND SUBSTITUTED AMMONIUM SALTS OF SAID ACID AS A BUILDER AND A WATER-SOLUBLE ORGANIC SYNTHETIC NON-SOAP DETERGENT SELECTED FROM THE GROUP CONSISTING OF ANIONIC, NONIONIC, ZWITTERIONIC, AMPHOLYTIC DETERGENTS, AND MIXTURES THEREOF, THE RATIO OF SAID BUILDER TO SAID DETERGENT BEING IN THE RANGE OF ABOUT 1:3 TO ABOUT 10:1, SAID COMPOSITION PROVIDING IN AQUEOUS SOLUTION A PH BETWEEN ABOUT 8 AND ABOUT 12.